Comorbidity, body mass index, and age and the risk of nonprostate-cancer- specific mortality after a postradiation prostate-specific antigen recurrence

BACKGROUND: Some men with a postradiation therapy (RT) prostate-specific antigen (PSA) recurrence will die of noncancer causes before developing metastases. Therefore, our ability to determine who would benefit from salvage hormonotherapy (HT) would be enhanced if an individual's risk of nonprostate-cancer-specific mortality were known. METHODS: Among 206 men with unfavorable-risk localized prostate cancer initially randomized to RT+/-HT, 87 men who experienced PSA recurrence were studied. Fine and Gray's competing risks regression was used to assess whether body mass index (BMI) and the Adult Comorbidity Evaluation-27 comorbidity level at randomization were associated with the risk of nonprostate-cancer-specific mortality after PSA recurrence, adjusting for age at recurrence. RESULTS: After a median postrecurrence follow-up of 4.4 years, moderate/severe comorbidity (adjusted hazard ratio [HR] = 3.15; P = .02), BMI ≥ median (27.4 kg/m²; adjusted HR=2.98; p=.04), and increasing age at recurrence (adjusted HR = 1.17; P = .03) were significantly associated with an increased risk of nonprostate-cancer-specific mortality. Five-year cumulative incidence estimates of nonprostate-cancer- specific mortality were as follows: 0% (95% confidence interval [CI] [0,0]) for low-risk patients (mild/no comorbidity and age<median [76.2 years] and BMI<median), 18.8% (5.8-31.8) for intermediate-risk patients (mild/no comorbidity and either age≥median or BMI≥median); and 37.9% (95% CI, 6.8-68.9) for high-risk patients (moderate/severe comorbidity; P = .03 overall). CONCLUSIONS: After a post-RT PSA recurrence, men with moderate/severe comorbidity and those who are obese or older face a substantial risk of nonprostate-cancer-specific mortality, and they could be considered for surveillance protocols with a plan to initiate salvage HT if the PSA rises rapidly (eg, PSA doubling time <6 months) or the patient develops clinically or radiographically evident disease.